1. Field of the Invention
The invention relates to safety and rescue systems. In particular, the invention relates to an emergency call device for a vehicle, an emergency call system, the use of an emergency call device in a vehicle, a method, a computer program product and a computer-readable medium.
2. Description of the Related Art
Vehicle emergency radio systems have been known for a long time. By way of example, DE 43 21 416 A1 discloses a vehicle emergency radio system which is based on the vehicle emergency radio system in the demonstrations project ARTHUR from 1989. To allow the position of the vehicle which has had an accident to be found regardless of the radio-related constraints, for example radio-related shadow effects in tunnels, at the location of the accident, provision is made    a) for the position-finding device to automatically ascertain the present position of the vehicle during the (entire) operating phase of the vehicle continuously, preferably at prescribed intervals of time, and to transfer the ascertained position data to the emergency transmitter, and    b) for the position data to remain stored in the emergency transmitter until new position data are received from the position-finding device.
In the event of an accident, the crash sensor (e.g. the airbag sensor) connected to a control unit (which is connected to a position-finding device and to an emergency transmitter, e.g. in the form of an appropriately modified car telephone) uses prescribed accident criteria to check whether or not an emergency signal needs to be sent. If the criteria are met, the crash sensor uses the control unit to send an enable signal to the emergency transmitter, which then uses the second antenna to send an emergency signal by radio together with the currently stored position data for the vehicle 1. In addition, it is possible for the crash sensor, upon the accident criteria being met, to prompt fresh determination of the vehicle position by the position-finding device and for these position data to be sent by the emergency transmitter together with the emergency signal. Finally, it is possible to use a travel pilot for position finding instead of a GPS device (Global Positioning System).
An emergency reporting apparatus which can recognize a plurality of signal formats, so that it can be installed generally in vehicles or models with different signal formats for the signals from an airbag device, is known from DE 101 37 670 A1. In this case, the airbag device is connected to a control unit and is activated by means of a LAN signal line, when a vehicle LAN bus line is used, or by means of a direct line which is not a LAN signal line when a vehicle without a vehicle LAN is involved. The airbag device outputs a status signal in order to identify whether a LAN connection or a direct line connection is involved.
In this case, the control unit provides the following functions:    1) An emergency call request is recognized from an operation signal from an emergency reporting key, an airbag deployment signal which is output by the airbag device in the event of a collision or accident, or an automatic emergency reporting signal on the basis of a fuel interruption signal.
2) The emergency reporting process is started by reading position information and other data from a memory unit.
3) The telephone number stored in the memory unit for the control center, such as for the police or for a rescue center which monitors the emergency reporting system, is read.
4) A telephone call is requested from the emergency reporting unit using this telephone number.
5) The transition to the conversation state is recognized when a response signal from the party corresponding to the telephone number or a signal which changes to the conversation state, such as a call connected signal, is received.
6) Position information and course data, which have been obtained from the position information capture/processing unit, and also the control center call signal are sent to the emergency reporting unit via the base station of the communication device.
In addition, DE 299 11 590 U1 discloses an apparatus which is permanently installed in a car and triggers from the airbag and sensors. The apparatus comprises a digital hands-free telephone—programd only for emergency calls—in a housing which, by virtue of its design, is suitable for installation in the internal lining of the car roof, and control lines to the external on/off switches, for example airbag or sensors. The emergency call is made automatically when one of the airbags or sensors in the car is triggered or the emergency call is triggered manually by means of a pushbutton switch or by further sensors installed in the vehicle. Preferably, the apparatus is accommodated centrally between the front and rear seats under the roof of the car.
A further emergency call device for vehicles which sends an emergency message to a rescue control center in the event of an accident ascertained by sensors in the vehicle, wherein the emergency message contains suitable information for the initiation of assistance measures, is known from DE 199 17 207 C2. To ensure that an emergency message is sent to a rescue control center even if the onboard electronics of the vehicle are destroyed by the accident, provision is made for the emergency call device to send a first message containing at least the geographical vehicle position in a critical driving situation ascertained by the sensors before an accident has actually occurred. If the critical driving situation subsequently does not result in an accident, the rescue control center is informed of the first message having lapsed by means of a second message, which is sent after a prescribed period of time has elapsed after the first message. The sensors can capture translational accelerations and/or angle-of-rotation accelerations by the vehicle and/or changes in the shape of the vehicle bodywork and/or braking processes and/or steering movements. An evaluation unit takes the sensor signals and uses threshold value decisions to infer whether a critical driving situation is present and whether an accident has arisen from a critical driving situation. The second message then contains information about the vehicle registration and/or the vehicle type and/or the severity of the accident and/or the number of vehicle occupants and/or acute illnesses in the vehicle occupants. After the second message, at least one further message can also be sent which contains further information about the course of events in the accident and/or the situation of the affected vehicle occupants.
A similar emergency call system with a transmitter/mobile telephone provided in the motor vehicle for the automatic transmission of an emergency call to an external receiving station and with at least one signal generator, wherein the transmitter and the signal generator are connected to a computation unit which activates the emergency call if there is an appropriate signal from the signal generator, is known from DE 199 22 730 A1. The emergency call system contains means for determining a degree of probability of an imminent accident with the signals from the signal generator, and the emergency call (together with the position ascertained by means of GPS navigation or compound navigation or by beacons at the edge of the road) can be activated when a limit value for the degree of probability is exceeded. In particular, the emergency call system contains, as a signal generator, measuring means connected to the computation unit for determining the relative speed and the distance of the vehicle from another vehicle or from an obstacle (radar system, infrared system), the computation unit being able to perform a comparison between the relative speed determined by means of the radar system and a maximum admissible value for the relative speed at the measured distance. The emergency call can therefore actually be activated before the accident if the maximum admissible relative speeds at a given distance are exceeded. However, it is also possible to store a plurality of pairs of values for a distance and for an associated maximum admissible relative speed in a memory and to determine the maximum admissible relative speed, including on the basis of the state of the road (optical sensors), by means of interpolation for example. In order to prevent false alarms, the computation unit is connected to at least one sensor for detecting an accident, particularly to an acceleration sensor on the airbag or to a temperature sensor (vehicle fire). The emergency call system also contains a timer which is connected to the computation unit and which is started when the emergency call is activated. If there is no signal signaling a collision from the sensor at the time at which the timer expires, the emergency call is automatically cancelled by means of the mobile telephone or the transmitter.
So as still to be able to safely send an emergency call using a radio telephone even in the event of a severe impact or collision of a vehicle, it is known practice from WO 03/042943 A2 to arrange an autarkic emergency call unit at a location in the vehicle which is particularly protected against damage through collision or impact. To this end, the emergency call unit is equipped with a dedicated battery, with a GSM transceiver and with a transmission and reception unit for setting up a short radio link to the radio telephone, and when an emergency call is triggered, the emergency call unit sends an emergency call via the short radio link to the radio telephone, which forwards the emergency call to an emergency control center by radio. Since the emergency call unit is not connected to the radio telephone by cable—electrical or optical fibers—but rather by means of a radio link, it is not possible for the situation to arise in which a collision causes the cables to be destroyed and the sending of an emergency call therefore to be rendered impossible. The radio transmission of an emergency call from the emergency call unit to the radio telephone is effected on the basis of the Bluetooth standard. An emergency call can be triggered by the trigger signal from an airbag, for example, as in the case of known emergency call devices. In addition, the emergency call unit may contain a sensor which detects a collision and immediately prompts the sending of an emergency call.
By way of example, the sensor provided may be a gyroscope which prompts the triggering of an emergency call from the emergency call device to the radio telephone not by means of electrical signals but rather in mechanical fashion. Since the gyroscope reacts right at the start of a collision, an emergency call is actually sent before the radio telephone is damaged or destroyed. The short time between the detection of a collision by the gyroscope and possible damage or destruction of the radio telephone by an impact suffices to allow the Bluetooth link to be used still to transmit all data which are relevant to the accident. If this time is no longer sufficient for sending an emergency call, the GSM transceiver in the emergency call device sends an emergency call.
Another option is for a commercially available radio telephone to be prepared to receive the emergency calls sent by the emergency call unit and to forward them to an emergency control center or for the user to use the mobile telephone to activate the emergency call unit and to trigger an emergency call. In this case, the mobile telephone acts more or less as a remote control for the emergency call unit.
In addition, portable emergency transmitters which can be activated by the user by pressing a key have been known for a long time. To send an emergency call within a few seconds without pressing keys using a portable mobile telephone or an emergency transmitter incorporated in a wristwatch, brooch or bracelet, it is known from DE 198 49 846 A1 that said mobile telephone/emergency transmitter has a voice recognition program, that at least one emergency telephone number is permanently stored and that input/recognition of a particular word prompts the emergency telephone number to be dialed automatically. In addition, the mobile telephone/emergency transmitter may be equipped with a pulse generator for finding the current position.
A mobile telephone/emergency transmitter which is known from EP 1 372 324 A2 is designed in a similar manner. In one embodiment described therein, various previously stored keywords are evaluated—in silent alarm mode—and recognition of one of the keywords prompts an emergency message to be sent to a rescue control center/police station via the mobile radio network.
Finally, U.S. Pat. No. 6,573,831 B2 discloses a monitoring apparatus in the vehicle in which a microphone is used to continuously pick up and store sounds in the area of the vehicle so as to be able to evaluate them after any accident which has occurred. The sounds captured by means of the microphone are themselves not used to trigger an emergency call in the vehicle, however.
As shown by the above acknowledgement of the prior art, differently designed vehicle emergency radio systems with or without position-finding or determination of a degree of probability of an imminent accident are known. Usually, it is necessary for the mobile telephone to be integrated into the vehicle electronics or to be coupled thereto by means of interfaces, or two radio telephones are necessary, as in the case of the subject matter of WO 03/042943 A2.
In addition, extensive precautions need to be taken with regard to unintentional trigger processes for an emergency call. Triggering using stored keywords on a mobile telephone/emergency transmitter carried by the user also fails if the road user is himself unable to do this after an accident. Therefore, what is missing in practice is a vehicle emergency radio system which can be used universally regardless of other technical circumstances and which triggers an emergency call automatically in the event of an accident.